Analysis of the outer divertor hot spot activity in the protection video camera recordings at JET

Aleksander Drenik, JET Contributors, Tommy Ahlgren

Tutkimustuotos: ArtikkelijulkaisuArtikkeliTieteellinenvertaisarvioitu

Kuvaus

Hot spots on the divertor tiles at JET result in overestimation of the tile surface temperature which causes unnecessary termination of pulses. However, the appearance of hot spots can also indicate the condition of the divertor tile surfaces. To analyse the behaviour of the hot spots in the outer divertor tiles of JET, a simple image processing algorithm is developed. The algorithm isolates areas of bright pixels in the camera image and compares them to previously identified hot spots. The activity of the hot spots is then linked to values of other signals and parameters in the same time intervals. The operation of the detection algorithm was studied in a limited pulse range with high hot spot activity on the divertor tiles 5, 6 and 7. This allowed us to optimise the values of the controlling parameters. Then, the wider applicability of the method has been demonstrated by the analysis of the hot spot behaviour in a whole experimental campaign.

Alkuperäiskielienglanti
LehtiFusion Engineering and Design
Vuosikerta139
Sivut115-123
Sivumäärä9
ISSN0920-3796
DOI - pysyväislinkit
TilaJulkaistu - helmikuuta 2019
OKM-julkaisutyyppiA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä, vertaisarvioitu

Tieteenalat

  • 114 Fysiikka

Lainaa tätä

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title = "Analysis of the outer divertor hot spot activity in the protection video camera recordings at JET",
abstract = "Hot spots on the divertor tiles at JET result in overestimation of the tile surface temperature which causes unnecessary termination of pulses. However, the appearance of hot spots can also indicate the condition of the divertor tile surfaces. To analyse the behaviour of the hot spots in the outer divertor tiles of JET, a simple image processing algorithm is developed. The algorithm isolates areas of bright pixels in the camera image and compares them to previously identified hot spots. The activity of the hot spots is then linked to values of other signals and parameters in the same time intervals. The operation of the detection algorithm was studied in a limited pulse range with high hot spot activity on the divertor tiles 5, 6 and 7. This allowed us to optimise the values of the controlling parameters. Then, the wider applicability of the method has been demonstrated by the analysis of the hot spot behaviour in a whole experimental campaign.",
keywords = "ITER-like wall, Image analysis, JET, Plasma-wall interaction, 114 Physical sciences",
author = "Aleksander Drenik and {JET Contributors} and Tommy Ahlgren",
year = "2019",
month = "2",
doi = "10.1016/j.fusengdes.2018.12.079",
language = "English",
volume = "139",
pages = "115--123",
journal = "Fusion Engineering and Design",
issn = "0920-3796",
publisher = "Elsevier",

}

Analysis of the outer divertor hot spot activity in the protection video camera recordings at JET. / Drenik, Aleksander; JET Contributors ; Ahlgren, Tommy.

julkaisussa: Fusion Engineering and Design, Vuosikerta 139, 02.2019, s. 115-123.

Tutkimustuotos: ArtikkelijulkaisuArtikkeliTieteellinenvertaisarvioitu

TY - JOUR

T1 - Analysis of the outer divertor hot spot activity in the protection video camera recordings at JET

AU - Drenik, Aleksander

AU - JET Contributors

AU - Ahlgren, Tommy

PY - 2019/2

Y1 - 2019/2

N2 - Hot spots on the divertor tiles at JET result in overestimation of the tile surface temperature which causes unnecessary termination of pulses. However, the appearance of hot spots can also indicate the condition of the divertor tile surfaces. To analyse the behaviour of the hot spots in the outer divertor tiles of JET, a simple image processing algorithm is developed. The algorithm isolates areas of bright pixels in the camera image and compares them to previously identified hot spots. The activity of the hot spots is then linked to values of other signals and parameters in the same time intervals. The operation of the detection algorithm was studied in a limited pulse range with high hot spot activity on the divertor tiles 5, 6 and 7. This allowed us to optimise the values of the controlling parameters. Then, the wider applicability of the method has been demonstrated by the analysis of the hot spot behaviour in a whole experimental campaign.

AB - Hot spots on the divertor tiles at JET result in overestimation of the tile surface temperature which causes unnecessary termination of pulses. However, the appearance of hot spots can also indicate the condition of the divertor tile surfaces. To analyse the behaviour of the hot spots in the outer divertor tiles of JET, a simple image processing algorithm is developed. The algorithm isolates areas of bright pixels in the camera image and compares them to previously identified hot spots. The activity of the hot spots is then linked to values of other signals and parameters in the same time intervals. The operation of the detection algorithm was studied in a limited pulse range with high hot spot activity on the divertor tiles 5, 6 and 7. This allowed us to optimise the values of the controlling parameters. Then, the wider applicability of the method has been demonstrated by the analysis of the hot spot behaviour in a whole experimental campaign.

KW - ITER-like wall

KW - Image analysis

KW - JET

KW - Plasma-wall interaction

KW - 114 Physical sciences

U2 - 10.1016/j.fusengdes.2018.12.079

DO - 10.1016/j.fusengdes.2018.12.079

M3 - Article

VL - 139

SP - 115

EP - 123

JO - Fusion Engineering and Design

JF - Fusion Engineering and Design

SN - 0920-3796

ER -